This invention relates generally to female terminals and more particularly to a low profile contact having a female receptacle which is insertable through a hole in a printed circuit board and which is constructed to receive male terminals having size and entrance angles of wide tolerances without appreciably altering the mechanical and electrical characteristics between the female receptacle and the inserted male terminal.
A particular type contact used extensively today, particularly with substrates such as printed circuit boards comprises at one end a female receptacle which fits securely within an aperture in a printed circuit board, and at the other end comprises a post or other type terminal which extends through the printed circuit board and forms a terminal for connection to additional conductors. Such additional conductors can be connected to the extended-through portion by wire wrap, solder or any other suitable method for securing a wire to such extended-portion. Components having male type terminals can then be mounted on the circuit board by inserting the male terminals into the female receptacles secured in the board.
In applications where space is limited, such as hand calculators, it is advantageous that the female portion of a contact have a low profile with respect to the surface of the printed circuit board, i.e., the receiving opening of said female portion should be close to the surface of the circuit board. Consequently, components mounted in such low profile contacts will also be positioned quite closely to the circuit board surface, thereby conserving valuable space.
To meet the foregoing needs, low profile receptacles have been developed. Specifically one such low profile contact means, which is stamped from a continuously fed supply of stock material, is generally cylindrical in shape and open at one end, with portions of the open end thereof being flared outwardly to provide an entrance for the mating male pin. The cylindrical portion comprises opposing tangs or finger-like elements which are secured to the rim of the open end of the female receptacle and are bent back upon themselves to extend inwardly towards each other in the center portion of the cylindrically shaped receptacle to receive and grip a male post inserted therebetween.
One such prior art structure is shown in U.S. Pat. No. 2,858,153 issued Aug. 24, 1973, to Coller et al. Another such prior art device is shown in application Ser. No. 589,092, filed June 23, 1975, by Robert Franklin Cobaugh et al and entitled "Low Profile Contact" and assigned to the assignee of the subject application.
In such prior art structures those finger-like contacts which are folded back upon themselves and extend into the interior portion of the cylindrically-shaped female receptacle generally have a straight, flat configuration. Accordingly, when a misaligned male pin is inserted therein, such male pin frequently will be misaligned and will make contact with one of the folded-over fingers near the point of folding, thereby producing large bending stress forces in such folding areas. Such large forces will deflect the folded-over fingers beyond their limits of elasticity to produce permanent distortion thereof, with resulting deterioration in the mechanical and electrical characteristics between the folded-over fingers and the male pins inserted therebetween.
It is to be understood that while the problem of damage to a female receptacle by a misaligned male pin has been discussed above with respect to a female receptacle mounted in a circuit board and even more particularly to a low profile type female receptacle, the problem of damage is much more general.